Cryptographic protection of information in a processing system

Abstract

A processor employs a hardware encryption module in the processor's memory access path to cryptographically isolate secure information. In some embodiments, the encryption module is located at a memory controller (e.g. northbridge) of the processor, and each memory access provided to the memory controller indicates whether the access is a secure memory access, indicating the data associated with the memory access is designated for cryptographic protection, or a non-secure memory access. For secure memory accesses, the encryption module performs encryption (for write accesses) or decryption (for read accesses) of the data associated with the memory access.

Description

BACKGROUND[0001]1. Field of the Disclosure[0002]The present disclosure relates generally to processors and more particularly to information security at a processor.[0003]2. Description of the Related Art[0004]In many processor applications, protection of information security is an important feature. For example, a processor can be used in a server in an Infrastructure As A Service (IAAS) environment, wherein the processor executes one or more virtual machines (VMs) and executes a hypervisor to partition the server hardware among the VMs and isolate the VMs from each other. Because different VMs may be executed on behalf of different customers, it is desirable that the information (instructions and data) employed by each VM be protected from access by other VMs. Conventionally, the hypervisor maintains isolation of VM information by maintaining separate memory page tables and other logical entities for each VM. However, flaws (e.g. bugs) in the hypervisor can cause the hypervisor its...

AI Technical Summary

Benefits of technology

[0018]In some embodiments the processor is employed in a processing system to execute different virtual machines (VMs), and to further execute a hypervisor to provide an interface between the VMs and the processing system's hardware, including memory. Because the VMs may be executed by distinct users (e.g. different customers), it is desirable that the VMs be isolated from each other such that one VM cannot access the information (instructions and data) employed by another VM. Conventionally, the hypervisor has been used to isolate the VMs by assigning each VM a dedicated portion of memory and other resources of the processing system for its private use. However, bugs in the hypervisor, or a hypervisor that has been maliciously modified to act as a vehicle for exploitation, can allow the hypervisor or a given VM to examine, or even alter, the information of another VM. Using the techniques described herein, the encryption module of the memory controller is employed to cryptographically protect the information of each VM from access by the hypervisor or by other executing VMs. Because the cryptographic protection is implemented in the hardware of the processor's memory access path (“below” the executing hypervisor), bugs in the hypervisor, or a malicious hypervisor, would provide access only to encrypted data that could not be understood or meaningfully interpreted.

Problems solved by technology

However, flaws (e.g. bugs) in the hypervisor can cause the hypervisor itself to be vulnerable to exploitation, allowing one VM to access the information of another VM.

Even in more private security environments, such as a personal computer, data stored in memory modules can be subject to theft, and the data stored therein subject to unauthorized access.

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